1. Field of the Invention
The present invention relates to the deployment of inflatable tubular structures and other dynamically deployed devices (xe2x80x9cDDDsxe2x80x9d), and more particularly, to a dynamically deployed device anchor and assembly that optimize the deployment position of a DDD by eliminating the need to affix the DDD directly to a vehicle structure.
2. Background of the Invention
Dynamically deployed devices, such as inflatable tubular structures (xe2x80x9cITSsxe2x80x9d), are widely used to protect vehicle occupants during rapid vehicle deceleration, such as the deceleration encountered in a collision. The DDDs used in vehicles are placed throughout the vehicle in strategic locations where occupants can be expected to impact hard components of the vehicle. Generally, DDDs are placed above and below the dashboard on both the driver and passenger side, and are placed along the sides of the vehicle at both head and hip levels. The lower DDDs protect the legs and hips of the occupant while the upper DDDs cushion the head and upper torso.
To adequately protect a vehicle occupant, the DDD must inflate and come to rest between the vehicle structure and the expected final location of the occupant during the collision. In conventional installations, a DDD is attached to a vehicle structure with cords or straps (hereinafter referred to as xe2x80x9ccordsxe2x80x9d), and is stowed in an uninflated state within a component of a vehicle, e.g., the roof rail. During a collision and upon deployment, the DDD inflates, emerges from its stowed location, and pulls taut the cords or straps that attach both sides of the DDD to the vehicle structure. In its deployed position, the DDD is centered between the two points at which the cords or straps are attached to the structure. Thus, the attachment points determine the final deployment location of the DDD.
In the typical automobile application, the ends of a DDD are mounted to a vertical or horizontal member of the vehicle structure. For example, to provide side impact protection for front and rear seat passengers, a DDD could be mounted to the A-pillar and either the C-pillar or D-pillar of an automobile. FIG. 1 illustrates this typical prior art installation, with the DDD attached to the A-pillar A and D-pillar D, and spanning the B-pillar B and the C-pillar C. Similarly, to provide side impact protection to front passengers only (e.g., in two-seat car), a DDD would be attached to A-pillar A and to either roof rail RR or B-pillar B of the vehicle. Thus, provided that the intended deployment location of the DDD is between two points on the vehicle pillar or roof rail, the DDD can be directly attached to the vehicle structure for optimal deployment.
However, often the vertical and horizontal vehicle members do not provide suitable DDD anchor points for several reasons, including component obstruction, protection zone concerns, and deployment characteristics. For example, a seat belt mechanism may obstruct the deployment or attachment of the DDD. Also, using a particular vehicle member may compromise the size of the protected zone. For example, some vehicle platforms place an occupant between the B-pillar and C-pillar. If the DDD must be mounted on the C-pillar, then the DDD cannot protect the full distance between the B-pillar and C-pillar (because of the attachment hardware and cord). Finally, with respect to deployment characteristics, the required speed and tension of deployment, both of which depend on attachment geometry, may preclude attachment to a vehicle member. For example, with vehicles that place an occupant between the B-pillar and C-pillar, the DDD could be anchored to a D-pillar to solve the protection zone concern and provide complete protection between the B-pillar and C-pillar. However, this solution creates negative deployment characteristics, increasing the time the DDD takes to reach its functional position and decreasing the maximum attainable DDD tension (because of the greater length between anchor points).
Vehicle members are also unsuitable anchor points when the optimal length and orientation of a DDD place the cord ends of the DDD somewhere other than along a vehicle structure member. For example, in the two-seater car A-pillar-to-roof-rail-attachment described above, the DDD""s final deployment position is necessarily diagonal. If, however, optimal DDD performance requires horizontal deployment, there may be no suitable vertical member on which to affix the DDD, e.g., if B-pillar B is not strong enough or contains other obstructing equipment.
Vehicles such as station wagons, sport utility vehicles, and other commercial utility vehicles also present problems with directly anchoring DDDs to a vehicle member. In these utility vehicles, a compartment of the vehicle typically is not intended for passengers. To provide complete protection in the passenger compartments such as the front and rear passenger seats, the DDD should preferably deploy the full length of the each compartment, making attachment of the DDD to the pillar behind the rear passenger compartment unsatisfactory (as described above). Thus, the DDD must attach to the rearmost pillar, e.g., the D-pillar in a utility vehicle, or to the section of the roof rail between the C-pillar and D-pillar. This attachment method requires a longer, more expensive cord or ITS on the DDD. In addition, the longer distance between attachment points detracts from DDD performance, increasing the time required to reach the functional position and magnifying oscillation. In contrast, having an intermediate anchor point just behind the rearmost pillar of a passenger compartment would allow the DDD to optimally deploy and provide full protection to the full length of each passenger compartment.
Thus, there remains a need for a device that anchors a DDD in an optimal position without relying on the direct attachment of the DDD to a vehicle structure. The device should adequately support the deployment of a DDD and should facilitate positioning of the DDD in a location that provides the most protection for the vehicle occupant.
The present invention is a dynamically deployed device anchor and assembly that provide a fixed attachment point offset from a vehicle member. The DDD assembly includes a DDD, at least one anchor pivotally attached to the DDD and a vehicle member, and a means for stopping the at least one anchor from rotating past a predetermined angle. In the preferred embodiment of the present invention, the anchor is a link or a cam pivotally fastened to a vehicle structure and the means for stopping rotation is a stop or a tether. A DDD cord is attached to the DDD anchor. Upon deployment, the DDD cord pulls the DDD anchor down around its pivot point and into a locked position against the means for stopping rotation. Once locked, the DDD anchor restrains the cord and provides a fixed attachment point offset from a vehicle structure member, or at least from the point at which the cam is pivotally fastened.
In a first preferred embodiment of the present invention, as shown in FIG. 2, the DDD anchor is a link with one end of the link pivotally attached to a roof rail and the other end attached to the DDD cord. The link is stored horizontally on the roof rail, and upon deployment, pivots down into a vertical position against a means for stopping rotation, e.g., a mechanical stop, as shown in FIG. 2. In a first alternate implementation of the first preferred embodiment, the means for stopping rotation is a tether. With the DDD cord pulling the link against the means for stopping rotation, the DDD anchor provides a DDD attachment point offset from the roof rail.
In a second alternate implementation of the first preferred embodiment, if the slack ratio (deployed length/undeployed length) of the DDD and DDD cord is low, making the undeployed and stowed DDD pull tightly against the attachment points, the DDD link can be configured with a slot in which a DDD cord fastener slides freely. The DDD is attached to the sliding DDD cord fastener. With the DDD link in the stowed position, the sliding DDD cord fastener is positioned closest to the DDD, thereby shortening the undeployed length between DDD attachment points. Upon deployment, the DDD cord pulls the link down, and at the same time, pulls the sliding DDD cord fastener to the bottom end of the pivoting DDD link. When the DDD link pivots against the means for stopping rotation and the sliding DDD cord fastener stops at the end of the DDD link, the DDD anchor provides a DDD attachment point offset from the roof rail.
In a second preferred embodiment of the present invention, the DDD anchor is a cam, e.g., a flat 90xc2x0 wedge-shaped piece. The cam is pivotally attached through its apex to the roof rail and is held in a stowed position before DDD deployment. Upon deployment, the cam is pulled by the DDD such that it rotates around its pivot attachment point and comes to rest against a means for stopping rotation.
Preferably, the cam is stored with its edge opposite the location of the DDD up against the roof rail. The DDD is attached to the corner of the cam up against the roof rail such that upon deployment when the cord pulls tight, the cam is pulled down. During deployment, the cam rotates and stops at 90xc2x0 where the other edge of the cam hits the roof rail, which functions as a stop, preventing the cam from rotating further. In this locked position, the cam provides a DDD attachment point offset from the vehicle roof rail. Optionally, in this configuration a mechanical stop is fastened to the roof rail to act as the means for stopping rotation.
In an alternate implementation of the second preferred embodiment, the cam is stowed above the roof rail and the DDD is attached to the lower comer of the cam. Preferably, the means for stopping the rotation of the cam past a predetermined angle is a stop affixed to the roof rail, or alternately, a tether. The DDD pulls the cam down and rotates the cam around its pivot attachment point until the cam is stopped by the means for stopping rotation.
Accordingly, an object of the present invention is to improve the positioning of a DDD to maximize occupant safety.
Another object of the present invention is to decrease the length of a DDD to shorten the duration of deployment and reduce DDD oscillation.
Another object of the present invention is to provide a fixed DDD attachment point that is offset from a vehicle structure member.
Another object of the present invention is to facilitate the optimal placement of a deployed DDD.
These and other objects of the present invention are described in greater detail in the detailed description of the invention, the appended drawings, and the attached claims.